<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

<div id="app">
    <h2>总价格：{{totalPrice}}</h2>
</div>

<script src="../../js/vue.js"></script>
<script>
    const app = new Vue({
        el: '#app',
        data: {
            books: [
                {id: 110, name: 'Unix编程艺术', price: 119},
                {id: 111, name: '代码大全', price: 105},
                {id: 112, name: '深入理解计算机原理', price: 98},
                {id: 113, name: '现代操作系统', price: 87}
            ]
        },
        computed: {
            totalPrice: function () {
                let result = 0;
                for (let i=0; i < this.books.length; i++){
                    result += this.books[i].price;
                }
                return result

                for (let i in this.books) {
                    this.books[i]
                }

                for (let book of this.books) {

                }
            }
        }
    })
</script>

</body>
</html>